Removing Blur from an Image

• US 20130223754A1
• Filed: 03/25/2013
• Published: 08/29/2013
• Est. Priority Date: 09/24/2008
• Status: Active Grant

• Current Assignee: Zhigu Holdings Limited
• Original Assignee: Microsoft Corporation
• Inventors: Yuan, Lu, Quan, Long, Sun, Jian, Shum, Heung-Yeung
• Granted Patent: US 8,750,643 B2
• Time in Patent Office: Days
• US Class Current: 382/255
• CPC Class Codes: G06T 2207/20016 Hierarchical, coarse-to-fine, multiscale or multiresolution image processing; Pyramid transform
• CPC Class Codes: G06T 2207/20028 Bilateral filtering
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening

Abstract

Embodiments related to the removal of blur from an image are disclosed. One disclosed embodiment provides a method of performing an iterative non-blind deconvolution of a blurred image to form an updated image. The method comprises downsampling the blurred image to form a blurred image pyramid comprising images of two or more different resolution scales, downsampling a blur kernel to form a blur kernel pyramid comprising kernels of two or more different sizes, and deconvoluting a selected image in the blurred image pyramid according to a Richardson-Lucy deconvolution process in which a bilateral range/spatial filter is employed.

Claims

1. A computing device comprising instructions stored thereon that are executable to

deconvolute a blurred image to form an updated image via a Richardson-Lucy deconvolution process utilizing a bilateral range/spatial filter that takes on smaller values as one or more of a spatial distance increases and a range distance increases.

2. The computing device of claim 1, wherein the instructions are further executable to utilize a filter reliant on an external guide image in the Richardson-Lucy deconvolution process in addition to the bilateral range/spatial filter.

3. The computing device of claim 2, wherein the instructions are executable to deconvolute the blurred image by

downsampling the blurred image to form a blurred image pyramid comprising images of two or more different resolution scales,

downsampling a blur kernel to form a blur kernel pyramid comprising kernels of two or more different sizes, and

deconvoluting a selected image in the blurred image pyramid;

and

wherein the guide image is an upsampled image from a previously deconvoluted next-lower resolution scale in a blurred image pyramid.

4. The computing device of claim 2, wherein the instructions are further executable to deconvolute the blurred image by

downsampling the blurred image to form a blurred image pyramid comprising images of two or more different resolution scales,

downsampling a blur kernel to form a blur kernel pyramid comprising kernels of two or more different sizes, and

deconvoluting a selected image in the blurred image pyramid;

and

wherein the guide image is a previously updated image from a same resolution scale in a blurred image pyramid as a current image.

5. The computing device of claim 2, wherein the instructions are executable to perform a plurality of inter-scale deconvolutions in which the guide image at a selected scale in the blurred image pyramid is an upsampled image from a next-lower scale in the blurred image pyramid.

6. The computing device of claim 5, wherein the instructions are executable to perform a plurality of intra-scale deconvolutions in which the guide image is a previously deconvoluted image from a same scale in the blurred image pyramid.

7. The computing device of claim 6, wherein the instructions are executable to perform the Richardson-Lucy deconvolution process by:

8. The computing device of claim 7, wherein ∇

E_B comprises a high pass filter as an additional filter for the Richardson-Lucy deconvolution process in an intra-scale deconvolution at each scale in the blurred image pyramid.

9. On a computing device, a method of deconvoluting a blurred image via a non-blind deconvolution, the method comprising:

iteratively downsampling the blurred image to form a blurred image pyramid comprising images of a plurality of different resolution scales;

at a lower resolution scale in the blurred image pyramid, deconvoluting a lower resolution image according to a Bilateral Richardson-Lucy (BRL) deconvolution process in which a bilateral range/spatial filter is employed;

upsampling the lower resolution image to form an upsampled image; and

at a higher resolution scale in the blurred image pyramid, deconvoluting the higher resolution image according to the BRL deconvolution process.

10. The method of claim 9, further comprising employing a filter reliant on an external guide image in addition to the bilateral range/spatial filter.

11. The method of claim 10, wherein the external guide image comprises a previously deconvoluted image from a same scale in the blurred image pyramid.

12. The method of claim 10, wherein the external guide image comprises an image that is upsampled from a previously deconvoluted image at a next-lowest resolution scale in the blurred image pyramid.

13. The method of claim 9, wherein the JBRL deconvolution process proceeds as following:

14. The method of claim 13, wherein ∇

E_B comprises a high pass filter as an additional filter for the BRL deconvolution process in an intra-scale deconvolution at each scale in the blurred image pyramid.

15. On a computing device, a method of deconvoluting an original blurred image to form an updated image, the method comprising:

iteratively downsampling the original blurred image to form a blurred image pyramid comprising i layers of blurred images of progressively lower resolution scales, wherein i=0 is a lowest-resolution scale;

for each resolution scale 0 to i;

performing an inter-scale Bilateral Richardson-Lucy (BRL) deconvolution process in which a bilateral range/spatial filter is employed;

performing one or more intra-scale BRL deconvolution processes in which the bilateral range/spatial filter is employed; and

upsampling the intra-scale deconvoluted image.

16. The method of claim 15, further comprising, for scales 1-n, employing an additional filter reliant on an external guide image.

17. The method of claim 16, wherein the external guide image comprises an image upsampled from a next-lowest resolution scale after deconvolution at the next-lowest resolution scale.

18. The method of claim 16, wherein the external guide image comprises a previously-deconvoluted image from a same resolution scale.

19. The method of claim 15, wherein upsampling the intra-scale deconvoluted image comprises performing a bicubic or bilinear interpolation to form an intermediate upscaled image.

20. The method of claim 15, further comprising employing high pass filter as an additional filter for one or more intra-scale JBRL deconvolution processes.